+1 on the Vest. It's rare that you'd race in a full jacket. For one thing the added wind resistance, compared to a tightly fit vest, is best avoided if possible.

However, you'll use a Vest a lot. By varying the combinations of base layers, jerseys, arm warmers, you can use the vest to cover a wider range.

Plus the vest is easier to stow in your pockets.

If it's really cold and rainy, you need a jacket, but you can make do with one that doesn't match the kit on those occassions.